SAT0593 INCIDENCE OF RHEUMATOID ARTHRITIS, PSORIATIC ARTHRITIS AND SPONDYLOARTHRITIS AND THEIR ASSOCIATED COMORBIDITIES IN A BELGIAN GP REGISTRY
Authors: Sofia Pazmino, Veerle Stouten, Patrick Verschueren, Pavlos Mamouris, Rene Westhovens, Kurt de Vlam, Delphine Bertrand, Kristien Van der Elst, Bert Vaes, Diederik De Cock
Journal: Annals of the Rheumatic Diseases (2019)

<h3>Background:</h3> Rheumatoid arthritis (RA), psoriatic arthritis (PSA) and spondyloarthritis (SPA) are the most common inflammatory rheumatic diseases and all of them are associated with a high burden of comorbidities. Incidence of these diseases and of their comorbidities are unknown in Belgium. <h3>Objectives:</h3> To determine incidences of disease and comorbidities in patient populations of RA, PSA and SPA in a General Practitioners (GP) setting. <h3>Methods:</h3> Data were obtained from Intego over a 13-year time interval from 1999 to 2012. Intego is a Flemish GP-based morbidity registration network hosted at the Academic Center for General Practice of KU Leuven, covering 2% of the Flemish general population, Patients classified under the International Classification of Primary Care codes L88 (rheumatoid/seropositive arthritis) and L99 (musculoskeletal disease other) were selected for this study. Experienced rheumatologists verified if the keywords mapped to these codes corresponded to a diagnosis of RA/SPA/PSA. The entry date of these diagnoses in Intego was considered "baseline". Yearly disease incidence and comorbidity incidence over 3 years are presented. The following comorbidities with high impact on outcomes like disability, costs, hospitalization and death were considered: lung disease, cardiovascular disease including myocardial infarction, stroke or other heart condition, hypertension, fracture of the spine/hip/leg, depression, diabetes mellitus, digestive disease including ulcers and stomach disorders and malignancies [1]. <h3>Results:</h3> Over a 13-year period, 817, 258 and 190 patients were included with a diagnosis of RA, SPA or PSA, respectively. The average incidence of RA was 0.47, of SPA 0.15 and of PSA 0.11 per 1000 person years. Fig1 gives the yearly incidence per disease. The RA cohort had a mean(SD) age of 57.7(17.2) with 68% being women. The SPA cohort had a mean(SD) age of 40.6(15.1) with 50% being women. The PSA cohort had a mean(SD) age of 47(13.2) with 48% being women. The comorbidity with the highest prevalence (23%) and incidence (29.6/1000 person years) in RA was hypertension. In the SPA cohort, digestive disease was most common at baseline (14%) and during follow-up (21.0/1000 person years). PSA patients presented most frequently with depression at baseline (18%) and during follow-up (9.8/1000 person years). RA patients presented with a higher number of incident cases of diabetes (17.7/1000 person years) compared to SPA or PSA patients. (See table 1) <h3>Conclusion:</h3> The incidence of RA appears to remain stable while incidence of PSA - and to a lower extent SPA - seem to increase over a 13-year interval. A control cohort will be formed to improve comparability of comorbidity presence, yet from these preliminary results we can determine that an important subpopulation of patients with rheumatic diseases already presents with significant comorbidities at baseline, or during 3-year follow-up. This study highlights the growing issue of multimorbidity in patients with musculoskeletal diseases and the importance of a holistic approach to manage these patients. <h3>References</h3> [1] England BR, Sayles H, Mikuls TR, Johnson DS, Michaud K. Validation of the rheumatic disease comorbidity index. Arthritis Care Res (Hoboken)2015;67(6):865-72. <h3>Disclosure of Interests:</h3> Sofia Pazmino: None declared, Veerle Stouten: None declared, Patrick Verschueren Grant/research support from: Unrestricted Pfizer Grant for Early RA research, Pavlos Mamouris: None declared, Rene Westhovens Grant/research support from: Bristol-Myers Squibb, Consultant for: Celltrion, Galapagos-Gilead, Kurt de Vlam Consultant for: Pfizer Inc, Consultant for: Johnson &amp; Johnson, Delphine Bertrand: None declared, Kristien Van der Elst: None declared, Bert Vaes: None declared, Diederik De Cock: None declared